Multiple petitions DS-160

My current h1b expires on Mid July 2015, and i have my renewed approved petition valid until July 2016, I am going to india in mid May 2015, while going for stamping my employer asked me to use current EAC number (i.e valid until july 2015) and asked me to present the future approval document to the VO so that i can get stamped from current day to end of future petition end date. Could you please clarify if this works.